Calorie burn at the gym

Ok, so I recently heard that at the gym, the exercise machines over estimate the calories you burn, especally the elliptical can estimate up to double what you've actually burnt in a session. I was told that I should buy a heart rate moniter to get an accurate idea of the calories I burnt.
Today at the gym I used a cross ttrainer/elliptical and the calories it said I burnt was 530 (i typed in my weight at the beginning)
According to the idea that it is an over estimate it should be 265 calories
But using a website that calculates net calorie burn based on age, height, weight, time exercising and average heart rate (which I knew as I held onto heart rate things the whole time and the machine gives an exercise summary at the end of a work out) it came out to 634 calories

Which one sounds right to people here? I don't want to over eat or under eat, as there is a hige difference between 265 and 614 calories. Any thoughts?

I used this website to calculate the calories based on heart rate
http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx

Replies

  • Makoce
    Makoce Posts: 938 Member
    Id love to know this answer too.
    I stalled weight loss for 2 months due to machine telling me calories
  • It's so frustrating! torn between over doing it and possibly going into this "starvation mode" I often hear mentioned, and getting in and thinking, well if I don't eat lots of food it's bad for me. Might just get a heart rate moniter. Justso expensive. And the only cheap one I've seen you have to keep it wet. That will look quite odd in the gym...
  • AccioFitness
    AccioFitness Posts: 244 Member
    I plan on investing in a heart rate monitor for this exact reason. I am really curious as to what others have to say though!
  • vorgas
    vorgas Posts: 741 Member
    If you don't know your VO2 Max, a HRM will also be innacurate. VO2 Max is the amount of oxygen your body can process, typically expressed in milliliters per kilogram of muscle. Because your HR is increasing in response to a demand for oxygen, obviously the more oxygen you can push at a given HR, the lower your HR will need to be.

    That being said, using a HR calculator will be far more accurate for aerobic exercise (HR > 50% and < 70% Max) than anything else.

    I've been on plenty of machines that come close to what a HRM will tell me. I think that 50% is a broad generalization and not accurate in many cases.

    As to keeping the HRM wet, it's probably just contacts on the back of the strap. You just wet them before you put it on. When you work up a sweat, it stays plenty wet :)
  • cndslee
    cndslee Posts: 256 Member
    A heart rate monitor is really the most accurate way to know the calorie burn you have at the gym. Yes the machines DO overestimate the calories. There is usually a 75 - 100 Calories less on my HRM than the machine shows - depends on what I do.Polar has a good HRM PF4 and it is reasonably priced. A HRM is one of the best investments I have made in myself!
  • pricesteve
    pricesteve Posts: 39 Member
    I bought a Polar FT7 HRM for this very reason and was quite surprised to find the gym equipment I use actually gave very similar readings to the monitor once you allow for the fact the HRM includes Calories you would have burned doing nothing as well as the extra calories burned by the exercise.